Field of the Invention
Embodiments of the present invention generally relate to a thin film transistor (TFT) and a method for manufacturing a TFT.
Description of the Related Art
Metal oxide semiconductors, such as zinc oxide (ZnO) and indium gallium zinc oxide (IGZO) are attractive for device fabrication due to their high carrier mobility, low processing temperatures, and optical transparency. TFTs made from metal oxide semiconductors (MO-TFTs) are particularly useful in active-matrix addressing schemes for optical displays. The low processing temperature of metal oxide semiconductors allows the formation of display backplanes on inexpensive plastic substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). The transparency of oxide semiconductor TFTs leads to improved pixel apertures and brighter displays.
Metal oxide semiconductors are susceptible to negative interactions with hydrogen and/or water. When the metal oxide semiconductor material is exposed to hydrogen or water, stability of the semiconductor layer becomes an issue. Additionally, it is difficult to produce repeatable results as the hydrogen interacts with the metal oxide and thus, each TFT may be different.
Therefore, there is a need in the art for stable metal oxide TFTs that can be reliably and repeatably produced.